SU1656644A1 - Alternating-to-constant voltage converter - Google Patents

Abstract

This invention relates to electrical engineering and can be used in secondary power supply sources. The purpose of the invention is to improve the shape of the output voltage by increasing the filtering efficiency of radio interference. The converter consists of two half-wave rectifiers connected in parallel on the input and in series on the output. Each of the rectifiers includes a resonant circuit made on a double-winding choke 9 (20), the first winding of which is shunted by a chain of capacitors 14, 15 (23, 24). Radio interference is attenuated by decoupling the input of the device from the output. This isolation is achieved by sequential power transmission of the network through the input 5.6 (1b, 17) and output 7, 8 (18, 19) diodes, first to the resonant circuit and then to the load. 1 il.

Description

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This invention relates to electrical engineering and can be used in secondary power supply sources.

The purpose of the invention is to improve the shape of the output voltage by increasing the filtering efficiency of radio interference.

 The drawing shows an electrical circuit for converting an alternating voltage into a constant voltage.

The converter includes two half-wave rectifier circuits connected in input and output in such a way that when they are turned on together, a full-wave rectification circuit is formed. In this case, the first rectifier contains input terminals 1, 2 for connecting an alternating current source, to which the input diodes 3.4 are connected with opposite electrodes. The output 5 and the total 6 pins are connected oppositely

electrodes are diodes 7, 8, the free terminals of the other electrodes of which are connected to the second winding of the chokes 9 (or transformer). Between the input terminals 1.2 and a chain of capacitors 10, 11 is included. Between the terminals 5. 6 a chain of capacitors 12, 13 is switched on, and between the free terminals of the electrodes of diodes 3, 4 a chain of capacitors 14, 15 is turned on, connected in parallel with the first winding of the Drossel 9 The second rectifier is constructed according to a similar scheme, but with the reverse switching on of the diodes and is connected to the first one in parallel along the input and in series along the output. In this case, the second rectifier includes the same elements as the first: diodes 16-19, choke 20 and chains of capacitors 21, 22, 23. 24 and 25, 26. The common connection points of the capacitors of all the chains of these rectifiers are connected to the common output.

About SP

about about ±

The Converter operates as follows.

When a positive half-wave voltage is applied to the input pins 1, 2, the diodes 3, 4 open and a current flows through them. The circuit from the first winding of the throttles 9 and the capacitors 14, 15 accumulates energy. Diodes 7, 8 are locked. Capacitors 12, 13 are discharged to the load. At the end of the half cycle, the input voltage changes. Diodes 3, 4 are locked, the current is stopped. With a further increase in the negative voltage due to the resonant properties of the circuit, it exceeds the output voltage at the capacitors 12, 13. In this case, the diodes 7, 8 are opened. When the voltage on the indicated circuit decreases (less than the output voltage), the diodes 7, 8 are closed. The output voltage is equal to the voltage of the capacitors 12, 13. The currents through the input and output diodes do not overlap, and therefore in each phase of the load supply at least one of the diodes is locked.

The resonant circuit can be tuned to higher harmonics of the input signal by selecting the parameters of the elements included in it, which helps reduce the capacitance and inductance of the output filters. The second rectifier works in a similar way, forming the output voltage from the negative half-wave of the supply voltage.

The converter is provided with galvanic isolation of the input from the output, which is carried out due to the periodic switching of counter-connected input and output diodes, which in the first half-period transfer energy from the network to the circuit, and the second - from the circuit to the load. At the same time, in each half-period, the load is disconnected from the network due to locked input or output diodes.

The attenuation coefficient of radio interference in each phase of the network is equal to the ratio of the capacitor capacitance at the output of the locked diode to the capacity of the locked diode. The attenuation of radio interference is achieved due to a two-sided limitation of the input voltage and a limitation of the width of the radio interference spectrum.

resonant circuit and does not depend on frequency.

Claims (1)

Claims of an AC-to-DC converter containing two input, two output and common terminals for connecting respectively an AC input voltage source and a load, two diodes, a two-winding choke and a filter capacitor, the first the input terminal is connected to the anode of the first diode, the cathode of which is connected to the beginning of the first winding of the throttles, the end of which is connected to the anode of the second diode, characterized in that, in order to improve forms of the output voltage by increasing the interference filtering efficiency, the third and fourth diodes are additionally introduced in it, as well as the second, third, fourth, fifth and sixth capacitors, the terminals of which are connected to the first and second respectively to the first and second input terminals, the third and the fourth to the first and second output pins, the fifth and sixth to the pins of the beginning and end of the first winding of the throttle, and the free pins of these capacitors are connected to a common terminal, and the pins of the beginning and end of the second winding of the drog The villages are connected respectively to the cathode of the third and the anode of the fourth diode, the free terminals of the anode and cathode of which are connected respectively to the first and second output pins.